It would definitely be safer to RMA the thing; something clearly was wrong.

If you want to try to keep it, check the SMART data and see what the reallocated sector count is like. If it's very low (and zero pending sectors), you can take the chance. If it's >100, return it. Between 10 and 100, it's your call.

I use smartctl under Linux; I know there are Windows tools for the same information.